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Professor Diesel

How to exercise an unused engine

By PMY Staff | Posted May 2012

Caring for engines after a not-too-long hiatus.

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How do I check for engines damaged by forgetting to open seacocks?

By PMY Staff | Posted April 2012

I left my marina with my seacocks closed...

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Are end-of-season oil changes really necessary?

By PMY Staff | Posted January 2012

Should we do end-of-season oil changes or can we stretch the old oil into the next season?

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How do I care for my unused engine?

By | Posted November 2011

I plan on being away from my boat for two to three months and during that time, I plan on having someone periodically run my diesels dockside...

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Does an increase in horsepower explain a rise in exhaust temperature?

By | Posted October 2011

  Question: I have a 1989 38-foot Bayliner with twin 175-hp Hino diesels that have been retrofitted with turbochargers, thus raising each engine to 210 horsepower. As I go...

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Can switching motor oil viscosity harm my engine?

By | Posted September 2011

  Question: The boys at the Ko Olina harbor are having a heated discussion concerning motor oil. Since Costco hit town, we’ve all been able to buy Chevron 15W-40 Delo...

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Using synthetic oils in older engines

By | Posted August 2011

  Question: I own a 1996 43-foot Hatteras with twin six-cylinder Detroit Diesel engines. I change the oil approximately every 100 hours of operation. At this point, I have 1,...

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Vintage Yanmars Running Hot

By | Posted June 2011

  Question: I have a 29 Phoenix with twin, 1984-vintage, 170-hp Yanmar diesels with 1,000 hours on them. While the boat seems to run fine, I have one issue. During operation...

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Idling diesel engines

By | Posted May 2011

Question: My mechanic friends tell me not to let my diesel engine idle for long. They say that it should either be under load or turned off. I hear a lot of diesel engines in...

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Trouble-shooting an overheating boat engine

By | Posted April 2011

Question: I have a 1990 Carver Yacht with two 375-hp Caterpillar 3208 diesels. The starboard engine works fine, but at 2000 rpm the port engine overheats. Once the temperature...

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Seasonal Storage For Fuel Tanks

By | Posted March 2011

  Question: When I took your one-day Introductory Diesel Maintenance Course several years ago, I forgot to ask one question: What is the best way to lay up a fuel tank for...

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Aluminum in engine oil

By | Posted February 2011

  Question: I just did my first oil analysis on my Cummins 6BTA diesel, and the results seem somewhat disconcerting. According to the report, there was aluminum in the oil at...

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Caterpillar 3208 low rpm

By | Posted January 2011

  Question: I have a 1989 Sea Ray with 375-hp Caterpillar 3208 diesels. Last year I overheated one of them and blew a head gasket. Overheating had been a problem for some...

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Onan genset spewing black smoke

By | Posted December 2010

Question: I have a 4-kW Marine Onan genset with 600 hours on it. If I let it run for a lengthy period it produces so much black smoke that a residue discolors the hull around the...

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Noisy Engines

By | Posted November 2010

Question: I have a pair of Detroit Diesel 6-71 TIBs in my 1990 Ocean 48 Super Sport. I love both the boat and the motors, but the Detroits have always been loud at the exhaust end...

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Twin Engine Temperature Disparity

By | Posted October 2010

Question: I have a 1994 Mainship 31 with a pair of 315-hp Yanmar diesels with 2,000 hours on them. While running at full throttle (about 33 knots) for five minutes, the starboard...

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Algae On My Racor

By | Posted September 2010

Question: While performing routine maintenance on my Caterpillar C7, I was surprised to find a substance about the size of a quarter at the top of my Racor—it looked like...

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Professor Diesel

By | Posted November 2009

Q. I have a 2003 Sea Ray Sundancer 420 and am moving from the New York City area to Florida soon. Do I need to do anything different in Florida in terms of boat maintenance? I am...

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Getting your engine ready for launch in the spring

By | Posted February 2009

  Question: I’ve always wondered if there was anything special I should do when getting my boat ready for launch in the spring. My mechanic says no, just start her up,...

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